We have previously found distinctively different and partially opposed behavioral syndromes in rats with extensive central NE lesions made with small, multiple injections of 6-OHDA and in rats with extensively lowered 5HT levels obtained with chronic PCPA or small multiple injections of 5,6 DHT. We have also found that animals in which smaller 6-OHDA or 5,6 DHT lesions are made and a prolonged recovery period allowed develop another set of characteristic behaviors related to partially recovered, "supersensitive" NE circuitry and partially recovered, "supersensitive" 5HT circuitry. We now propose to further study these four distinctively different behavioral syndromes which follow relatively selective monoaminergic disruptions, and to study the effects of enriched environmental housing and of pharmacological agents on the recovery process. We will compare the recovery process, as measured by behavioral and biochemical tests, in animals allowed to recover in isolated cages with that in animals allowed to recover in a more natural environment (involving a non- crowded group colony). We will also observe the social behaviors, competition for food, and patterns of self-isolation in rats recovering from relatively selective NE or 5HT lesions in an attempt to better describe the symptomatology resulting from different monoaminergic disruptions and to better monitor the stages of recovery. Once this is accomplished and distinctive behavior patterns have been isolated, we will study the effects of pharmacological agents, including tricyclic antidepressants, on the time course of this recovery process and test the possibility that medications effective at one stage in recovery may be deleterious at other stages. In a separate project, preliminary results indicating opposed effects of d-amphetamine and methylphenidate on an observing response in rats (the rearing response) will be pursued and experiments conducted to specify the anatomical locus and pharmacological basis of these effects.